The sustained strikes on Ras Lanuf create an impasse on the eastern front. Combined with tanks and artillery backing government forces 30 miles west, the warplanes halt the rebels' advance.

Reporting from Ras Lanuf, Libya — The day dawned with the shrill whine of a warplane. Then there was a rough growl as a jet fighter, heard but not seen, swooped low on another bombing run.

Everyone in this rebel-held oil city — fighters poised on antiaircraft batteries, terrified residents huddled in their seaside bungalows, doctors in their worn blue scrubs at the hospital — tensed and waited.

And then the explosion. This one sent a shudder across the coastal highway and through the empty homes of those who already have fled. It dirtied the morning air with sand and shrapnel and debris.

The rebels' cranky old antiaircraft guns sounded, but their furious efforts left only black smudges in the bright desert sky. The shabab, young rebel fighters, fired their assault rifles skyward. But it was a hollow exercise; the attacker was long gone.

Libyan government aircraft Tuesday launched at least five airstrikes on Ras Lanuf, and hospital officials said at least 20 people were injured. That brought the toll in the fighting here since Sunday to 10 dead and about 75 wounded.

The sustained airstrikes have created an impasse on the Libyan conflict's eastern front, at least for the moment. Combined with tanks and artillery backing government forces about 30 miles west, the warplanes have halted the rebels' advance toward Tripoli, the capital.

The attacks appear designed to pin down rebels and cow a civilian population that supports the rebellion against Libyan leader Moammar Kadafi. Even when just blasting craters in the desert, they have a terrorizing effect.

Opposition leaders have asked the United Nations to approve a no-fly zone to prevent Kadafi's air force from flying over Libya. U.S. officials have questioned its potential effectiveness and said it would first require attacks to destroy Kadafi's air defenses. And U.N. action would require the assent of Russia and China, which are reluctant to intervene in other nations' affairs.

Outside Ras Lanuf Medical Center, Dr. Awad Ghweiry watched in dismay Monday as a jet unleashed a bomb that exploded a short distance away. The concussion washed over residents and attendants outraged by the attack, which demolished a two-story home abandoned by its occupants the day before.

"No fly; we want a no-fly zone," Ghweiry said in English. And then he shouted, "Oh, that was close!" as he spotted a gray plume of smoke erupting from the explosion.

"Where is America?" Ghweiry asked. "They're killing our people while America talks and talks but does nothing."

Each of the airstrikes on the 21st day of the eastern rebellion reinforced a sense of fear and frustration in a city defended by lightly armed rebels with no air force.

The warplanes would scream overhead, the shabab would sprint madly for cover in the dunes, the gun batteries would erupt, and a resounding boom would spew out a dark column of smoke. Each attack left the rebels focused on surviving, not advancing westward toward Kadafi's hometown, Surt, and then on to Tripoli, the capital.

About 30 miles west, rebel fighters skirmished with Kadafi's forces in Bin Jawwad, a desert outpost seized by rebels Saturday but lost to a fierce government counterattack Sunday.

Neither side gained an advantage, according to rebels returning from the fighting. Kadafi's forces used helicopter gunships, tanks, rockets and artillery to hold them at bay, they said.

"This is like a water gun compared to what we're up against there," said Akram Gaith, 27, brandishing a machine gun he said he had fired near Bin Jawwad.

Control of the small town would allow the rebels to assault Surt, 95 miles west, a garrison town that blocks the coastal highway to Tripoli. As of Tuesday, the rebels' farthest sustained advance from the east was a checkpoint about five miles west of Ras Lanuf constituting the first defense against any government attempt to overrun the strategic city.

Despite the arsenal unleashed by Kadafi's forces, the rebels seemed to maintain their characteristic bravado and enthusiasm. Some had arranged spent antiaircraft shells along a sidewalk to spell out "Free Libya" in Arabic and English.

"The more he hits us, the braver we get," Gaith said as he scanned the sky for signs of an attacking warplane.

The airstrikes did not hit the oil and petrochemical complex or port in Ras Lanuf. It is not in Kadafi's interest to damage the oil facility when his forces are fighting to win it back.

But warplanes dropped two bombs that thudded down late Monday near Bishr, 70 miles into rebel-held territory, residents said. And a family of six hit Monday by an airstrike in Ras Lanuf died in the attack, said two doctors interviewed at a hospital in Ajdabiya, about 150 miles east of here and 95 miles short of Benghazi, the main eastern city.